1. Field of the Invention
This invention is directed to the conversion of methanol to mercaptans, sulfides, disulfides and ethylene over spent shale. Ethylene is a very desirable product used in the manufacture of polymers. The sulfur compounds so obtained can be used, for example, as odor-giving compounds to natural gas and in the manufacture of solvents. More particularly, the present invention is concerned with a process of which methanol mixed with water and spent shale is converted to other useful compounds.
2. Description of the Prior Art
Spent shale disposal is a major concern in oil shale development because of the volume of material to be disposed of and the potentially harmful materials it contains. Depending on the oil yield from the shale, above ground retorting could require as much as 18.5 tons of oil shale mined per cubic meter of oil produced. Although mining and crushing reduces the oil shale packed density and most of the organic material is removed by retorting, the spent shale volume nevertheless becomes greater than the original volume. Thus, spent shale as a waste product is expected to be available in increasingly large volumes as a result of continually expanding surface retorting operations. The spent shale may be used, for example, in the backfilling of mine areas or other land reclamation operations which are viewed currently as a major avenue for its disposal. Other such uses, as in road construction and as a filler, are also known.
The specific composition and properties of the spent shale depend on where it was obtained as well as on the retorting method by which it was caused to be spent. Generally speaking, oil shale consists of sedimentary inorganic material that contains complex organic materials of high molecular weight sometimes referred to as kerogen. Thermal decomposition is the primary means used to recover liquid products from the oil shale. Pyrolysis, or retorting of the oil shale, yellow gaseous liquid and solid products. The liquid which is produced by the pyrolysis is in the form of vapor or mist as are the non-condensable hydrocarbon gases. The organic carbon which is not recovered as compounds in the gaseous or liquid products is converted to a coke-like deposit and becomes part of the spent shale. The spent shale that remains after retorting of little or no economic value, is the material utilized in this invention.